原标题：Maxim MAX11905 20位单路全差分SAR ADC解决方案

　　Maxim公司的MAX11905是20位1.6Msps单路全差分SAR ADC,具有极好静态和动态性能,SNR为98.3dB,THD为-123dB,INL为6 LSB,不丢失码20位分辨率.主要用在测试和测量,自动化测试设备(ATE),医疗仪表,过程控制和工业自动化,数据采集系统,通信设备和以电池为能源的设备.本文介绍了MAX11905优势和主要特性,框图,应用框图以及MAX11905差分评估板主要特性,电路图,材料清单和PCB设计图.

　　The MAX11905 is a 20-bit, 1.6Msps, single-channel, fully differential SAR ADC with internal reference buffers. The MAX11905 provides excellent static and dynamic perfor­mance with best-in-class power consumption that directly scales with throughput. The device has a unipolar differ­ential ±VREF input range. Supplies include a 3.3V supply for the reference buffers, a 1.8V analog supply, a 1.8V digital supply, and a 1.5V to 3.6V digital interface supply.

　　This ADC achieves 98.3dB SNR and -123dB THD, guar­antees 20-bit resolution with no-missing codes and 6 LSB INL (max).The MAX11905 communicates data using a SPI-compatible serial interface. The MAX11905 is offered in a 20-pin, 4mm x 4mm, TQFN package and is specified over the -40 ℃ to +85 ℃ operating temperature range.

　　MAX11905优势和主要特性:

　　High DC/AC Accuracy Provides Better Measurement Quality 20-Bit Resolution with No Missing Codes

　　±6 LSB INL and ±1 LSB DNL Maximum at 20 Bits

　　98.3dB SNR and 98.1dB SINAD at fIN= 10kHz

　　-123dB THD at fIN= 10kHz

　　High Sampling Rate SAR Architecture Enables Fast Settling and Acquisition 1.6Msps Throughput with No Pipeline Delay

　　Integration Simplifies Design Integrated Reference Buffers, VREF = 2.5V to 3.6V

　　±VREF Unipolar Differential Analog Input Range

　　Scalable Ultra-Low Power Supply Reduces Power Consumption 9mW at 1.6Msps

　　Flexible Low-Voltage Supplies Save Cost 1.8V Analog and Digital Core Supply

　　1.5V to 3.6V Digital Interface Supply

　　3.3V REFVDD Reference Buffer Supply

　　Flexible, Industry-Standard Serial Interface and Small Package Reduce Size SPI-/QSPI™-/MICROWIRE®/DSP-Compatible

　　20-Pin, 4mm x 4mm, TQFN Package

　　MAX11905应用:

　　Test and Measurement

　　Automatic Test Equipment

　　Medical Instrumentation

　　Process Control and Industrial Automation

　　Data Acquisition Systems

　　Telecommunications

　　Battery-Powered Equipment

　　图1.MAX11905框图

　　图2.MAX11905应用框图

　　MAX11905差分评估板

　　The MAX11905 differential evaluation kit (EV kit) demonstratesthe MAX11905, 20-bit, 1.6Msps, single-channel,fully differential SAR ADC with internal reference buffers.

　　The EV kit uses the MAX44205, a low-noise fully differentialoperational amplifier. The EV kit includes a graphicaluser interface (GUI) that provides communication fromAvnet’s ZedBoard™ development board for the XilinxZynq®-7000 SoC. The ZedBoard, not included with theEV kit, must be purchased through Avnet, Inc.

　　The ZedBoard communicates with the PC through anEthernet cable using Windows XP®-, Windows Vista®-,Windows® 7-, or Windows 8/8.1-compatible software.

　　MAX11905差分评估板主要特性:

　　●● Peripheral Module and FMC Connector for Interface

　　●● 75MHz SPI Clock Capability through FMC Connector

　　●● 37.5MHz SPI Clock Capability through PeripheralModule Connector

　　●● Sync In and Sync Out for Coherent Sampling

　　●● On-Board Input Buffer (MAX44205)

　　●● On-Board +3.0V Reference Voltage (MAX6126)

　　●● Windows XP-, Windows Vista-, Windows 7-, andWindows 8/8.1-Compatible Software

　　图3.MAX11905差分评估板系统框图

　　MAX11905差分评估板材料清单:

　　详情请见:

MAX11905.pdf

MAX11905DIFEVKIT.pdf